The present invention relates to liquid electrolyte batteries and, more particularly, to a filling pod and a method for supplying fluid to such a battery.
A typical liquid electrolyte battery, such as a lead acid battery, includes a plurality of battery cells, each cell including at least one electrode submergible in the liquid electrolyte fluid. For example, a conventional 12-volt battery includes six 2-volt cells. Different battery applications may require different battery configurations. The battery also includes a battery housing having a cover portion substantially enclosing the battery cells and defining a cell port communicating with each of the cells and through which liquid electrolyte fluid is suppliable to the cell.
For optimal battery performance, each electrode is preferably completely submerged in the liquid electrolyte fluid, promoting a maximum degree of electricity-generating electrochemical reaction within each cell of the battery. However, electrolyte fluid is lost from each cell due to outgassing, which occurs during charging of the battery. To maintain the optimal level of battery performance and to maximize the service life of the battery, the electrolyte level in the battery must be regularly checked, and, if the electrolyte level is below the desired level, water must be added to replenish the electrolyte fluid. Accordingly, the electrolyte level in the battery is monitored and adjusted after charging of the battery.
In some constructions, the battery includes a vent cap member to close each cell port. To replenish the electrolyte fluid in the battery, the vent cap is removed from each cell, and electrolyte fluid is supplied to each cell separately through the individual cell ports. The vent caps are then replaced.
In some other constructions, a separate filling device is provided for each cell in the battery. A filling device may replace each conventional vent cap, and the separate filling devices are connected by flexible conduits to a fluid source so that fluid may be supplied to each filling device and to the corresponding cell. Such filling devices are disclosed in U.S. Pat. Nos. 1,791,152; 1,878,223; 4,353,968; 4,424,263; and 4,522,896 and in published PCT Application No. WO 98/40653.
In yet other constructions, a series of filling devices are constructed integrally with the battery or with the battery cover. Such constructions are illustrated in U.S. Pat. No. 3,722,087 and in published PCT Application No. WO 98/40653.
Battery-powered vehicles, such as for example, golf carts and utility vehicles, require periodic charging and replenishment of liquid electrolyte in the batteries. In most cases, the individual cells are replenished one at a time, for example, by an operator using a xe2x80x9cwatering gunxe2x80x9d, a water hose or a cup. In typical filling circuits, the filling circuits and procedures require connection of the circuit to a fluid source, either pressurized or in a vacuum arrangement, the source being located off board the vehicle. Flow of fluid through the circuit is caused by pressurized supply fluid or a vacuum applied to the filling circuit.
One problem with the above-described battery including conventional vent cap members is that, because the battery is typically supported on a battery-powered vehicle or device in a position which does not permit easy access to the battery, it is difficult to monitor the electrolyte level and to replenish the electrolyte fluid in each cell of the battery. Also, for a multiple cell battery, it is inconvenient and time consuming to remove each vent cap, check the electrolyte level in the cell, replenish the electrolyte fluid in the cell, as necessary, and replace the vent cap. Because these replenishment operations are difficult and time consuming, an operator may not replenish the electrolyte level as often as necessary, reducing the performance and service life of the battery.
One problem with the above-described separate filling devices is that the junction between the separate filling devices and the separate conduits provide areas in which leaks or blockages may occur. Also, the flexible conduit used to connect such separate filling devices is subject to being damaged or pinched, possibly preventing the flow of electrolyte to the separate filling devices and to the associated battery cell. In addition, installation of the separate filling devices and proper connection of the flexible conduits between the separate filling devices is inconvenient and time consuming. Further, because of the difficult-to-access position of these filling devices on the vehicle, an operator may not conduct the necessary maintenance to ensure proper operation of the filling devices and of the connecting conduits.
One problem with the above-described filling devices which are constructed integrally with the battery and/or with the battery cover is that such devices are not usable with existing batteries as a substitute for the separate vent caps or for the separate filling devices. Instead, a new battery including such integral filling devices is required to implement such a fluid replenishment system.
The present invention provides a filling pod, a vehicle and a method of supplying fluid to a battery which substantially alleviate one or more of the above-described or other problems with the existing batteries and filling devices. More particularly, the present invention provides a filling pod for supplying fluid to a battery and having a fluid supply member for each cell and a channel in fluid communication between each fluid supply member and a fluid source. In some constructions, the filling pod is configured to be removably mounted on the cover portion of an existing battery.
In particular, the present invention provides a filling pod including a filling pod housing having a filling pod port fluidly connectable to a fluid source for receiving fluid from the fluid source, a first fluid supply member fluidly connectable to a first cell, a second fluid supply member fluidly connectable to a second cell, and an integral channel in fluid communication between the filling pod port, the first fluid supply member and the second fluid supply member. The channel includes a first channel portion in fluid communication between the filling pod port and the first fluid supply member and a second channel portion in fluid communication between the filling pod port and the second fluid supply member. When fluid is supplied to the filling pod through the filling pod port, a first amount of fluid flows through the first channel portion to the first fluid supply member and to the first cell, and a second amount of fluid flows through the second channel portion to the second fluid supply member and to the second cell.
Preferably, the channel fluidly connects the filling pod port, the first fluid supply member and the second fluid supply member in series. The first channel portion may extend between the filling pod port and the first fluid supply member, and the second channel member may extend between the first fluid supply member and the second fluid supply member and fluidly connect the filling pod port to the second fluid supply member. Also, the channel may fluidly connect the filling pod port, the first fluid supply member and the second fluid supply member such that, when fluid is supplied through the filling pod port, the first amount of fluid flows through the first fluid supply member and to the first cell before the second amount of fluid flows to the second fluid supply member and to the second cell.
Preferably, the filling pod housing further defines a second filling pod port through which fluid flows from the filling pod. The channel may fluidly connect the first filling pod port, the first fluid supply member, the second fluid supply member and the second filling pod port in series, and the second filling pod port may be fluidly connected to the fluid source to supply any excess amount of fluid from the filling pod to the fluid source.
Preferably, the first filling pod port and the second filling pod port are alternatively and selectively fluidly connectable with the fluid source to receive fluid from the fluid source. Also, the filling pod ports are preferably positioned in recessed portions defined by the side wall of the filling pod housing so that the filling pod ports are protected from being damaged.
The filling pod housing may further define vent passages fluidly connected with the channel and fluidly connectable with the cells, a relief chamber for collecting gas, and relief passages fluidly connectable between the vent passages and the relief chamber. Also, the filling pod may further include valves regulating flow of gas through the relief passages.
Also, the invention provides a combination for supplying fluid to a battery, the combination including a battery, and a filling pod for supplying the fluid to the battery. The battery may include a battery housing having a cover portion substantially enclosing cells, the cover portion defining cell ports communicating with the cells and through which fluid is suppliable to the cell. Preferably, fluid supply tubes provide the fluid supply members, and the fluid supply tubes are preferably insertable into the cell ports to fluidly connect the filling pod with the cells. The combination may further include a locking arrangement for locking the filling pod to the battery. Preferably, a battery locking member and a filling pod locking member are engageable to releasably lock the filling pod to the battery.
In addition, the present invention provides a vehicle including a frame supported for movement over ground, a motor supported by the frame and for powering the vehicle, a battery supported by the frame and electrically connectable with the motor to supply power to the motor, and a filling pod for supplying fluid to the battery. The vehicle may further comprise a second battery supported by the frame and electrically connectable to the motor to supply power to the motor, and a second filling pod for supplying fluid to the second battery. Also, the fluid source may be supported on the frame.
Further, the present invention provides a method of supplying fluid to a battery including the acts of providing a filling pod for supplying fluid to the battery, fluidly connecting the filling pod to the battery including fluidly connecting the first fluid supply member to the first cell and fluidly connecting the second fluid supply member to the second cell, fluidly connecting the filling pod port to a fluid source, and supplying fluid from the fluid source to the battery through the filling pod including supplying a first amount of fluid through the first channel portion to the first fluid supply member and to the first cell and supplying a second amount of fluid through the second channel portion to the second fluid supply member and to the second cell.
In the supplying act, the act of supplying a first amount of fluid may occur before the act of supplying the second amount of fluid. Also, the act of fluidly connecting the filling pod to the battery may include inserting a first fluid supply tube into the first cell port to fluidly connect the filling pod with the first cell and inserting a second fluid supply tube into the second cell port to fluidly connect the filling pod with the second cell. The method may further include the act of locking the filling pod to the battery. The locking act may include releasably locking the filling pod to the battery.
One independent advantage of the present invention is that, even with the battery and the filling pod supported in a difficult-to-access position on the vehicle, an operator can easily replenish electrolyte fluid in the battery. Electrolyte fluid is simply added to the filling pod, and the cells are replenished with the electrolyte fluid, as necessary.
Another independent advantage of the present invention is that the filling pod does not include separate filling devices connected by separate conduits, reducing the likelihood of leaks and blockages occurring. Also, because flexible conduits are not required between the fluid supply members, the likelihood of a blockage resulting from damage or pinching of a conduit is reduced.
Yet another independent advantage of the present invention is that, in some constructions, the filling pod of the present invention is configured to be substitutable for the conventional vent caps of existing batteries and may be used with existing batteries without requiring modification or replacement of the battery.
One problem with the above-described battery-powered vehicles and devices which do not include a filling circuit is that individual cells must be replenished one at a time with, for example, a water hose, a time consuming method. This results in inconsistent filling of the cells, with some cells being under-filled and other cells being over-filled. In over-filled cells, acid may overflow into the work area and cause damage or corrosion to components of the vehicle.
One problem with the above-described filling circuits and procedures is that, when the batteries are charged, a separate fluid hook-up step is required before the liquid electrolyte can be replenished in the batteries.
Another problem with the above-described filling circuits and procedures is that a separate source of pressure is required to supply fluid to the filling circuit. Such a separate pressurized source may be a pump or a vacuum connected to the filling circuit.
Yet another problem with the above-described filling circuits and procedures is that, each time the batteries are charged, the separate fluid source must be connected to the filling system, and fluid must be replenished, even if only a small amount of fluid must be replenished.
The present invention also provides a system for supplying fluid to a battery, a vehicle and a method for supplying fluid to a battery which substantially alleviate one or more problems with the above-described filling systems and procedures. More particularly, the present invention provides a fluid supply system in which the gas produced during charging causes fluid flow through the system.
In particular, the present invention also provides a system for supplying fluid to a battery in a vehicle powered by the battery, the vehicle including a vehicle frame supporting the battery, the battery including a battery cell, fluid being transmittable to the cell, gas generated during charging of the battery being transmittable out of the cell. The system is defined as including a tank for holding fluid, and a hydraulic circuit connecting the battery to the tank. The hydraulic circuit is defined as including an inlet conduit connectable between the tank and the cell, and an outlet conduit connectable between the cell and the tank, gas produced during charging of the battery causing fluid flow through the outlet conduit and to the tank. Preferably, the outlet conduit collects gas transmitted from the cell in the form of gas bubbles with fluid entrapped between the bubbles, whereby the bubbles flow to the tank due to pressure build-up in the battery causing flow of fluid through the hydraulic circuit during charging.
A further independent advantage of the present invention is that the fluid supply system consistently and conveniently replenishes liquid electrolyte in the batteries.
Another independent advantage of the present invention is that the fluid source is supported on the vehicle. Therefore, when the batteries are charged, a separate fluid hook-up step is not required before the liquid electrolyte can be replenished in the batteries. The fluid supply system may automatically replenish the batteries.
Yet another independent advantage of the present invention is that in some constructions and for some aspects of the invention, the fluid supply system utilizes the pressure of the gas produced during charging to cause fluid flow through the fluid supply system. Therefore, a separate source of pressure, such as a pump or a vacuum, is not required.
A further independent advantage of the present invention is that in some constructions and for some aspects of the invention, the fluid supply system automatically replenishes the necessary fluid to the batteries when necessary and each time the batteries are charged. The operator is only required to add fluid to the system when no fluid remains in the fluid source after replenishment.
Other independent features and independent advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.